Bacterial Zoonoses Flashcards
What bacterium causes Cat Scratch Disease?
Morphology
Bartonella henselae
Curved gram neg rod. Motile.
What is Perinaud’s Syndrome?
What is it associated with?
Associated w/ CSD.
Ocular granuloma, conjunctivitis, and/or preauricular lymphadenopathy. Causes fever. May spread to abdominal lymph nodes, liver, spleen, or bones.
What is Bacillary angiomatosis?
What is it associated with?
Bartonella stimulates VEGF / angiogenesis → tuft of blood vessels. Friable. Bleed easily. Looks like Kaposi sarcoma. May occur inside the body as well → risk of internal bleeding.
Caused by CSD.
What is Peliosis hepatis?
What is it associated with?
Blood-filled cystic lesions develop in liver / spleen. Associated w/ hepatosplenomegaly, abdominal pain, and nausea.
Caused by CSD.
What AB is used for CSD?
What about bacillary angiomatosis?
Azithromycin - penetrates lymph nodes well. Intracellular penetration.
BA: Doxycycline or erythromycin
What bacterium causes plague? Morphology Endemic area in US Transmission Diagnosis Treatment Prevention
Yersinia pestis
Gram neg red w/ bipolar staining
Most cases occur in southwest US (New Mexico)
Transmitted via fleas, handling cats, eating rodents
Diagnosis - gram stain, culture, signs (neutrophilic leukocytosis, DIC, organ failure)
Treatment
• Aminoglycosides – streptomycin (DOC) or gentamicin
• Tetracycline / fluoroquinolones for meningitis, pleuritis, or myocarditis
• Beta lactams work in vitro, but NOT in vivo
• Aspirate the buboes if fluctuant (moveable / compressable)
Prevention
• Inactivated vaccine for occupational exposures or travel (rare)
• Vaccination of cats (rare)
• Insecticides / rodent control
• PPDs
What bacterium causes Tularemia? Morphology Endemic areas in US What animals transmit? Mode of transmission Prodromic sxs Specific sxs Diagnosis Treatment Prevention
Francisella tularensis
Gram negative bipolar rod (just like Yersinia)
Endemic to Arkansas / Missouri (Martha’s vineyard in Massachusetts)
Transmitted via ticks / rabbits (type A) or mammals / reptiles / birds (type B). Ticks can pass transovarially.
•Transmission – skin contact, ingestion (food / game, or water), and inhalation. Much smaller titer needed for inhalation than ingestion.
Prodrome sxs - fever, chills, headache, malaise
Specific sxs - ulceroglandular, oculoglandular, exudative pharyngeal, systemic typhoidal, and pneumonic.
•Treatment
• Aminoglycosides – streptomycin (DOC) or gentamicin
• Oral alternatives – ciprofloxacin or doxycyline
•Prevention
• Live attenuated vaccine for high risk pxs such as lab workers
• Insecticides, PPDs, cooking game meats thoroughly
What bacterium causes Leptospirosis? Morphology Animal reservoirs Endemic site in US Transmission Sxs 3 main disease states Diagnosis Treatment Prevention
Leptospira interrogans
Spirochete w/ bent / hooked ends
Dogs, cattle, pigs in US. Rats globally. Persists in renal tubules w/ prolonged excretion into urine.
Hawaii is most common site in US. Risk w/ recreational water use.
•Transmission – mucosal contact w/ urine of infected animal in water or mud is most common (even aerosolization). Also direct animal contact. High risk in slaughter house.
•Sxs - BIPHASIC FEVER, flu-like illness, headache, myalgia, malaise, abdominal pain, nausea, diarrhea, petechiae (vasculitis), conjunctival hemorrhage
•Anicteric leptospirosis - 90% of cases. Flu-like sxs.
•Weil Disease (icteric) - more severe w/ liver dysfunction / jaundice, renal insufficiency, and hemorrhage. AST / ALT are NOT elevated.
•Severe PUlmonary HEmorrhage Syndrome (SPHS)
•Diagnosis
• Serology
• Culture - special media.
• Dark field microscopy - neg result does NOT rule out diagnosis.
• PCR
•Treatment
• Beta lactams, then tetracycline: Ampicillin, amoxicillin, doxycycline
• IV penicillin G for severe disease
• Post-exposure prophylaxis – 1 week of penicillin or doxycycline
• Jarisch-Herxheimer rxn – caused by AB’s
•Prevention
• Avoid stagnant water, contact w/ animal urine
• Doxycycline prophylaxis for travel to Hawaii / Panama
• Vaccination of animals protects against clinical disease but it does NOT prevent shedding of the organism, so humans may still be at risk.
Brucellosis Morphology Strains in specific animals / areas. Which is most severe? Transmission Sxs Long-term sequelae Diagnosis Treatment
Gram neg coccobacillus
•B arbortus in cattle in Mexico
• B melitensis in goats in Mediterranean / Middle East
• B melitensis causes most severe disease, then suis, then abortus, then canis.
•Transmission – animal reproductive tissues / fluids, aerosolization, and needle sticks w/ RB51 cattle vaccine in vets. Risk for immigrants / travelers. Also in unpasteurized milk / soft cheeses.
•Sxs - Undulating fever, night sweats, profound weakness, arthralgia, myalgia, GI sxs, headaches. Sxs better in the morning. May cause epididymitis, orchitis, and miscarriage.
Diagnosis - culture / serology
•Treatment – doxycycline (TMP/Sulfa for kids) + rifampin for 6 weeks. Needle sticks should be treated prophylactically w/ 3 weeks of doxycycline
